Organic field-effect transistors (OFETs) have garnered widespread attention as devices where low material weight and flexibility are critical factors. The construction of such devices has involved organic semiconductor molecules based on polyacenes and oligothiophenes, as well as their hybrids. See Payne, M. M. et al., J. Am. Chem. Soc. 2005, 127, 4986-4987; Meng, H.; et al., J. Am. Chem. Soc. 2005, 127, 2406-2407; and Fichou, D. J. Mater. Chem. 2000, 10, 571-588. The majority of efforts to design and affect the performance of OFETs have focused on strategies to control solid-state structure. Many reports have underscored the importance of extended face-to-face stacking with short intermolecular separations that maximize p-orbital overlap. See Garnier, F. Syn. Met. 1996, 81, 163-171; Facchetti, F., et al., J. Am. Chem. Soc. 2004, 126, 13480-13501; Wu, Y., et al., and Appl. Phys. Lett. 2005, 86, 142102(1-3)
In this context, synthetic efforts to promote face-to-face solid-state stacking have focused on the functionalization of semiconductor molecules (e.g. pentacene, oligothiophene) with groups intended to direct the assembly process to the prerequisite packing. See Turbiez, M., et al., J. Chem. Eur. J. 2005, 11, 3742-3752; Moon, H., et al., J. Am. Chem. Soc. 2004, 126, 15322-15323; and Meng, H., et al., Adv. Mater. 2003, 15, 1090-1093. The intermolecular forces used to promote such arrangements have thus far been relatively weak, being based on van der Waals and/or dipole-dipole interactions. The most successful implementation of this strategy has, arguably, involved pentacene, where steric effects provided by bulky substituents prevented C-H . . . p forces. See Anthony, J. E., et al., Org. Lett. 2002, 4, 15-18; Sheraw, C. D, et al., Adv. Mat. 2003, 15, 2009-2011; and MacGillivray, L. R. CrystEngComm, 2004, 6, 77-78. A much greater p-orbital overlap was achieved, along with a lower anisotropic resistance perpendicular to the ring system (see Anthony, J. E., et al., J. Am. Chem. Soc. 2001, 123, 9482-9483), as compared to pure pentacene. However, the amount of p-orbital overlap cannot be correlated to the size and position of the functional groups, owing to a difficulty to control slipping along the pentacene short axis. See Anthony, J. E., et al., Org. Lett. 2002, 4, 15-18; Sheraw, C. D, et al., Adv. Mat. 2003, 15, 2009-2011; and MacGillivray, L. R. CrystEngComm, 2004, 6, 77-78. At the same time, reports have suggested a need to incorporate relatively strong intermolecular forces within such semiconductor lattices in order to suppress charge carrier scattering by lattice vibrations (See Dimitrakopoulos, C. D.; Malenfant, P. R. L. Adv. Mat. 2002, 14, 99-117. Collectively, these observations attest to the sensitivity of crystal packing to changes to molecular structure and create a challenge to devise methods that employ stronger intermolecular forces that control face-to-face stacking as a means to optimize the performances of organic semiconductor solids.
Currently there is a need for organic semi-conducting materials. Such materials will be useful, for example, in electrical devices, such as organic field-effect transistors, display devices, computer chips, plastic paper, and smart cards.